A Laser Triangulation Displacement Sensor Based on a Cylindrical Annular Reflector
Round 1
Reviewer 1 Report
This manuscript proposes a measurement model for a laser displacement sensor based on a cylindrical annular reflector to reduce the influence of laser characteristics on measurement and improve the accuracy of displacement measurement. The experiments verified that the repeatability error of this method is below 0.02%, and the accuracy is improved compared to traditional laser triangulation displacement sensors. The topic is meaningful and the manuscript is well organized.
The comments for the manuscript as below:
1)The repeatability is significantly improved. Please discuss in details and identify how much.
2)The figures in the manuscript needs be in right position that is close to the contents.
3)The language is suggested to be polished before it is accepted.
Author Response
Dear reviewer,
Thank you for giving me an opportunity to revise my manuscript, and we appreciate you very much for your positive and constructive comments and suggestions on our manuscript. We are writing to submit our revision paper and response your comments accordingly.
Comment 1: The repeatability is significantly improved. Please discuss in details and identify how much.
Response to comment 1: The first comment your put up is to discuss how much the measurement repeatability has improved in detail. We appreciate this suggestion very much, so we added some related contents in our revised manuscript, on the part of 4.2 Single-point repeatability measurement experiment. We also highlighted them and make a short illustration beside it. We referred on two measurement models which mentioned their measurement uncertainties, one is from Gao’s research [1], another is from Zhang’s research [2]. Gao conducted his experiment within the measurement range of 16mm using his measurement model and achieved the uncertainties of each point of less than 1um. After the calculation of repeatability using the formula (23) proposed in the manuscript, his results repeatability was below 0.01875%, also below 0.02%. But the model proposed in my manuscript is easier to achieve than his under the premise of we achieve the same level of measurement accuracy, and it consumes shorter time in calculation.
Fig 1. Highlighted content in Gao's paper
While in Zhang’s research, the standard deviations of his two measurement systems were 0.018 and 0.015 pixels respectively. And the corresponding uncertainties were less than 0.1085% and 0.0941%, the results repeatability of my measurement models is obviously greater.
Fig 2. Highlighted content in Zhang's paper
To provide a strong explanation, We have sent you these two papers in which we highlighted the related content in the attachment of our response.
Reference:
- Gao J, Wang X, Eckstein J, et al. High precision ring location for a new rotationally symmetric triangulation sensor[J]. International Journal of Information Acquisition, 2005, 2(04): 279-289.
- Zhang, H.; Zhang, Y.; Tao, W.; et al.; Rotational symmetric triangulation sensor based on an object space mirror. Optical Engineering, 2011, 50(12): 124401-124401-7.
Comment 2: The figures in the manuscript needs be in right position that is close to the contents.
Response to comment 2: As for your second comment, we am sorry if it disturbs you due to our figures. And we adjusted all figures in this manuscript carefully in our revision, at the same time we corrected some errors in the figures which we made notifications in our manuscript. Thank you for your advices.
Comment 3: The language is suggested to be polished before it is accepted.
Response to comment 3: We have paid a lot of dedication to polishing the language in this manuscript. It’s the first time of the first author to write SCI paper in English, and actually she has lots of confusions while writing. We feel sorry if the language in this manuscript disturbs you during review. Thank you for your tolerance. We truly cherish for your suggestions.
We have modified the paper as you suggested, and uploaded the revision to the system. Please check it. Thank you for your guidance.
Best regards,
Jiaqi Li
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The manuscript describes new simplified design of the rotational symmetric laser triangulation sensor. It is interesting and well described approach. But I have few remarks to the manuscript content.
References 1-5, and others are not accessible for readers in English.
Reference 10 is not valid.
Ref [13] refers to Journal of Image and Graphics inexistent paper
Figure 2 is difficult to read. There are not indicated parameters mentioned in text as L distance or alfa angle. All figures have low resolution even in zooming in. Text in Figures and its description miss capitals.
Text font in paragraph behind the relation (16) is different.
Geometry parameters listed in Table 2 are optimal results of NAGA-II algorithm?
Why you evaluate ring's radiuses and sensitivity value to so many decimals?
You evaluated a maximum incoherent irradiance, but you have not mentioned the simulated laser power nor the laser spot size.
There is a graphical error in line 334.
Is there any difference in pixel deleting in the first and the second sub iteration?
There is type error in the Figure 9.
What are geometrical tolerances and off-center placement of the aluminum ring and how it affects the image processing?
It would be fine to change the Figure 12 to inverse colors and to mark positions at least in the Figure description.
I don’t agree with conclusion that Figure 13 (a) show a linear relationship between the radius of the imaging 419 ring and the displacement of the measured object. It is visually nonlinear function.
I also don’t understand why fine detection repeatability expressed using standard deviation is better (smaller value) than for coarse detection in Figure 13 (b).
I assume the manuscript is acceptable after minor revision.
Author Response
Dear reviewer,
Thank you for providing us with such valuable and constructive feedback. Given the extensive comments you provided, we have crafted a detailed response letter addressing your remarks and questions, which we've attached for your perusal. Please find it in the attachments.
Best regards,
Jiaqi Li
Best regards,
Jiaqi Li
Author Response File: Author Response.pdf
Reviewer 3 Report
This manuscript proposes a measurement model for a laser displacement sensor based on a cylindrical annular reflector. A physical prototype is designed through parameter optimization using NSGA-II, and a two-step detection algorithm is proposed for the imaging ring of the prototype. This research has some potential for application, but it still needs some improvement. Here are some of my suggestions:
1、Authors should pay attention to the format of the article,
a. It is best to maintain consistent fonts in the figures and tables. (Table 1)
b. The font of the serial number of the formula does not correspond to the main text.
c. Larger font size in lines 197-201.
2、The resolution of Figure 4 is too low, is this a simulation result? Are they linear and how linear are they?
3、At what distance were each of the circles in Figure 10 acquired? What is the difference between them? Are images 6 & 1 in the same position?
4、The authors give a confidence interval in Eq. 23, what is the value taken in the final result? (Line 401)
5、The conclusion states that "the method resulting in sub-pixel level detection results", but there is no description in the manuscript to support this conclusion, the authors need explain this.
6、The author's descriptions of the figures are generally too brief, I personally would recommend adding more description to the images and captions to show the results, e.g. how was the radius of the circle measured? Is the measurement the inner or outer ring? Adding some schematics would be better.
Author Response
Dear reviewer,
Thank you for providing us with such valuable and constructive feedback. Given the extensive comments you provided, we have crafted a detailed response letter addressing your remarks and questions, which we've attached for your perusal. Please find it in the attachments.
Best regards,
Jiaqi Li
Author Response File: Author Response.pdf
